ESTRO 2025 - Abstract Book

S3692

Physics - Quality assurance and auditing

ESTRO 2025

Figure 1: Axial schematic of the virtual phantom.

Results: 42 submissions were received from 22 centres.

Figure 2 shows the ratio between the normalised responses from Type-C TPS dose algorithms and the normalised response from EGS-MC (for a 6MV beam only). Most submissions were within ±2% agreement of EGS-MC, across the different material assignments tested. Variability was found across different phantom-configurations ranging from the smallest being water-muscle 0.998 to 1.003 (with water as the outer region, muscle the inner insert) and the lung-muscle combination being the largest at 0.995 to 1.021.

Fig. 2 The dispersion of normalised results / normalised Monte-Carlo for different phantom-configurations (Type-C 6MV responses only).